Shifting arrangement, particularly for typewriters



Jan. 1, 1963 K. CHVATLINSKY SHIFTING ARRANGEMENT, PARTICULARLY FORTYPEWRITERS Filed April 17, 1961 5 Sheets-Sheet 1 INVENTOR parka-Z J.Fri ro- Jan. 1, 1963 K. CHVATLINSKY 3,071,233

SHIFTING ARRANGEMENT, PARTICULARLY FOR TYPEWRITERS Filed April 17, 1961a Sheets-Sheet 2 Jan. 1, 1963 K. CHVATLINSKY 3,071,233

SHIFTING ARRANGEMENT, PARTICULARLY FOR TYPEWRITERS Filed April 17, 19613 Sheets-Sheet 3 United States Patent 3,071,233 SHIFTING ARRANGE-ll"ENT, PARTICULARLY FOR TYPEWRITERS Kurt Qhvatlinsky, Wilhelmshaven,Germany, assignor to ()lympia Werke AG, Wiihelmshaven, Germany FiledApr. 17, 1961, Ser. No. 103,554 Claims priority, appiicatien GermanyApr. 16, 1%!) 21 Ciairns. (61. 197- 74) The present invention relates toa shifting arrangement, particularly for typewriters and similarmachines where either the paper carriage or the type lever carrier, isshifted from a normal lower case position to an upper case position, andback.

The shifting arrangements according to the prior art which serve thispurpose, have the disadvantage that the shifted element is rapidlystopped in its end positions, so that the impact creates shocks andundesired bouncing back of the shifted element. These effects have adetrimental eifect on the straightness of the typed lines, and produceconsiderable noise. Other shifting arrangements of the prior art requirea very complicated structure which increases the production cost andrenders repairs diflicult.

It is one object of the present invention to overcome the disadvantagesof the known shifting arrangements, and to provide a shiftingarrangement of simple construction capable of an almost noiselessoperation, and reliably holding the shifted element in its endpositions.

Another object of the present invention is to provide a shiftingarrangement for shifting an element of a typewriter between an uppercase position and a lower case position by the force of a rotary-powerroll and under control of a shift key without requiring any manual forcefor shifting the shifted element.

Another object of the present invention is to provide a shiftingarrangement in which resilient means effect initial movements to startthe operation, while the main part of the movement is carried out underthe action of power means.

Another object of the present invention is to control the movement of ashiftable element in such a manner that the movement of the shiftableelement is slow before the shiftable element arrives in its endspositions.

Another object of the present invention is to obtain the optimal speedvariation of the shiftable element during its movement.

With these objects in view, the present invention relates to a shiftingarrangement which is particularly suited for shifting the carriageelement or the type lever carrier element of a typewriter between thelowercase position and the upper case position. One embodiment of theinvention comprises in addition to the shiftable element, operatingmeans preferably including a cam with an arcuate cam track, movablebetween two end positions and connected to the shiftable element forshifting the same; biasing means, preferably a spring, connected to theoperating means and urging the same toward a dead center positionlocated intermediate the two end positions; a manually operated shiftkey member having two positions for holding the operating means, andparticularly the cam, in the end positions thereof against the action ofthe biasing means; and power means which cooperate With the operatingmeans.

In each of the end positions of the operating means, the biasing springmeans urge the same to move through an intermediate position toward thedead center position when the shift key is manually shifted from one ofits positions to the other position thereof. When the operating meansarrives in one of the intermediate positions, the power roll engages theoperating means and moves the same through its dead center position tothe other end 3fl'? 1,233 Patented Jan. 1, 1963 position where it isagain blocked by the shift key memher so that the spring cannot turn theoperating means back in the opposite direction toward the dead centerposition. As soon as the shift key is released, the operating means isalso released, and moves first under the action of the biasing spring,and then under the action of the power roll through the dead centerposition to the first end position thereof, where it is again blocked bythe shift key member from returning in opposite direction of the actionof the biasing spring.

In the preferred embodiment of the invention, the cam is turnable and isconnected to a lever on which the biasing spring acts. The lever isconnected. to a drive wheel which cooperates with the power roll. Thecam has a cam track slot which cooperates with an adjustable camfollower on the shiftable element. It is particularly advantageous tomake the cam track slot adjustable by forming the cam of two parts, oneof which is adjustable.

In the preferred embodiment of the invention, the cam track has two endportions which are substantially concentric to the turning axis of thecam, and are connected by sinusoidal cam track center portion. Due tothis shape of the cam track, the movement of the shifted element is slownear its end positions where it is under the action of the biasingspring, and rapid while it is driven by the power roll. The concentricend positions also hold the shiftable member in the upper and lower casepositions, respectively.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing, inwhich:

FIG. 1 is a fragmentary side view, partially in section, illustrating anembodiment of the shifting arrangement according to the presentinvention in its normal position in which the type lever carrier is inthe lower case position;

FIG. 2 is a fragmentary side view corresponding to FIG. 1, but showingthe shifting arrangement in a differ ent position in which the typelever carrier is in the upper case position; and

FIG. 3 is a fragmentary perspective view illustrating the shiftingarrangement of the present invention in the normal position of rest on areduced scale.

Referring now to the drawings, a type lever carrier 2 is mounted on theWalls 14. and la of a typewriter frame for substantially verticalmovement between a lower case position shown in FIG. 1 and an upper caseposition shown in FIG. 2. The type lever carrier 2 includes two lateralarms 2a and 2b, and a central segment-shaped slotted portion 3 in whichthe type levers 4 are mounted for turning movement between a normalinoperative position shown in solid lines in FIGS. 1, 2 and 3 and aprinting position abutting the platen of the paper carriage as shown indash and dot lines in FIGS. 1 and 2. Holding plates 6, 6a are secured bythreaded means 5 and 5a to the lateral arms 2:: and 2b and carry fixedthreaded spindles 7 and 7a. Two nut means 8, 8a and 9, ha arerespectively mounted on the threaded spindles 'i and 7a, which alsocarry washers 10, 10a and 11, 11a. Buffer springs 12, 12a and 13, 13aare mounted on the spindles 7, 7:: between the washers 1t and 11. Thelateral walls 1 and 1a of the frame support brackets 14 and 14a whichinclude yoke portions, and pairs of legs 15a, 16a and 15b, 16b whichhave forked end portions abutting the outer washers it? and 11. When thetype :lever carrier 2 is in its normal position shown in FIG. 1, thenuts 8, 3a abut the'inner washers 19, 10a and compress the springs W 12asince the inner washers 1t 1 3a are shiftable on the spindles 7, 7a,while the nuts 8, 8a are adjustably secured to the threaded portions ofthe spindles 7, 7a. It is evident that in the upper case position of thetype lever carrier 2 shown in FIG. 2, the lower buffer springs 13, 13aare compressed in a corresponding manner.

In the region of the center of carrier 2, a forwardly proj'ectingbracket 17 is fixed, on which a member including a U-shaped portion 19and an arm 19a is turnably mounted so that its position can be adjustedby turning an eccentric screw 18. Arm 190: carries a rotary cam followerroller 20.

A cam 23 is fixed on a shaft 21 which is mounted for turning movement inthe side walls 1 and 1a of the frame. Cam 23 has a cam track slot 23areceiving cam follower roller 20.

A double armed-lever 22 is fixed to shaft 21 and turns with the samebetween two end positions in which the cam follower is respectivelylocated in the two end portions of the cam track 23a. As clearly shownin the drawing, the end portions of the cam track 23a extend transverseto each other and substantially concentric to the turning axis of cam 23which is defined by shaft '21. However, the end portions of cam trackslot 23a are spaced different radial distances from the turning axis ofcam 23, and are connected by a center cam track portion of sinusoidalconfiguration.

It is evident that turning of shaft 21 with cam 23 from the positionshown in FIG. 1 to the position shown in FIG. 2, will force cam followerroller 2t to move from a position farther spaced from shaft 21 to aposition closer spaced from shaft 21 so that the type lever carrier 2 ispulled down. During the last part of the movement of the carrier, thebuffer springs 13, 13a are compressed and dampen the motion. Due to thefact that the arcuate center portion of the cam track 23a has a greaterradius of curvature near its end, the movement of the carrier 2 isslower near its end positions. The substantially tangential direction ofthe end portions of cam track 23a assures that the carrier '22 is notdisplaced even if there is a slight relative movement between camfollower 2t) and cam 23 while the carrier is in one of its endpositions.

The exact shape of the cam track 23a can be adjusted since an adjustablecam plate 25 is adjustably mounted on the main part of cam 23 andsecured to the same by an eccentric screw 24-. A guide pin 23' on themain part of cam 23 slides in a slot 25' of cam plate 25 so that camplate 25 is accurately guided. Cam plate 2 has an open cam track slot24a which together with the slot in the main part of cam '23, forms thecam track slot 23a. By adjustment of cam plate 24, the radial distancebetween slot 24a and shaft 21 can be adjusted whereby the distance ofthe displacement of the carrier 2 can be adjusted. It will be understoodthat one of the end portions of cam track slot 23a, is actuallyconstituted by the cam slot 24a of the cam plate 24.

A coil spring 26 is secured to a stud 1c on the frame of the machine,and to the arm 22a of lever 22. Arm 22a extends at an obtuse angle tospring 26 in both end positions of cam 23 shown in FIGS. 1 and 2. Consequently, spring 26 is tensioned in both positions, and will bias lever22 to turn to a dead center position in which lever arm 22a extends inthe direction of spring 26 and along a line connecting shaft 21 withstud 10. A link 27 is articulated to lever arm 22b and connected by apivot pin 28 to a control member or drive wheel 29 so that the same isalso biased to turn out of the position shown in FIGS. 1 and 2 under theaction of spring 26. Drive Wheel 29 is mounted for turning movement on ashaft 29a and has two recessed peripheral portions, and intermediate thesame two toothed portions which are shaped and positioned to cooperatewith the teeth of a rotary power roll 36 which is mounted in the frameof the machine and driven in a conventional manner by an electric motor,not shown.

When the type lever carrier 2 is in one of its end positions, and thecam follower roller 20 is located in one of the end portions of camtrack slot 23a, lever 22 is positioned to tension spring 26, while oneof the recesses of the drive wheel 29 is located opposite the power rollso that the same cannot engage the drive wheel 29 and rotate the same.

A manually operated member including a lever 32 has an arm 32:; which issupported for turning movement on a shaft 31 in the frame of themachine. A spring 34 is secured to arm 322 and to a fixed projection 33in the frame, so that the shift key member 32, 35 is held in its normalposition shown in FIGS. 1 and 3.

Lever 32 has two arms 32a, 32b respectively provided with transversebent-over blocking projections 32c and 32d. When the shift key member32, 37 is in its normal position shown in FIGS. 1 and 3, blockingprojection 320 is located below the projecting pivot pin 28 and engagedby the same under the action of spring 26 which tends to turn lever 22and drive wheel 29 which is connected by link 27 to lever 22. Suchturning movement of drive wheel 29 is prevented by the projection 320 aslong as the shift key 35 is not depressed. As best seen in PEG. 2,blocking projection 32a is located in the region of pivot pin 28 whenshift key 35 is depressed, and also blocks movement of lever 22 andturning movement of drive wheel 29.

An arresting key member 36 with a key portion 37 is turnably mounted ona pin 40 on lever 32, and is held in position by a spring 38. A bookshaped portion 361) on the arm 36a engages a stop 39 when key 37 isdepressed instead of key 37. In this manner, shift key 35 is arrested inits depressed position.

Operation The carrier 2 with the type levers 4 is normally in theposition shown in FIGS. 1 and 3 in which lower case characters areprinted. Cam follower 20 is at one end of the cam track, buffer springs12, 12a, are compressed, spring 26 is tensioned, and tends to turn cam23 through lever 22 and shaft 21, but operating means 21, 22, 23, 27, 29are prevented from turning movement towards the dead center position bythe abutment of pivot pin 28 on the projection 320 of the shift keymember 32, 35. One recess of the drive wheel 29 is located opposite thepower roll 30 so that the drive wheel 29 is spaced from the power means,and cannot be driven.

When shift key 35, or arresting key 37, is depressed so that lever 32 isshifted to the position shown in FIG. 2, the blocking projection 32cmoves away from the pivot pin 28, and the blocking projection 32dassumes a position located in the path of pivot pin 28 during turningmovement of drive wheel 29.

As soon as pivot pin 28 is released by projection 32c, lever 22 is nolonger blocked, so that spring 26 turns the operating means 21, 22, 23,27 with control member or drive wheel 29 in clockwise direction towardthe dead center position in which arm 22a and spring 26 extend in a lineconnecting shaft 22 with stud 10. However, when lever 22 reaches theintermediate position between the end position shown in FIG. 1 and thedead center position, wheel 29 is turned through link 27 and pivot means28 far enough to an intermediate position between the initial endposition thereof and the position which drive wheel 29 assumes in thedead center position of the operating means so that one of the toothedportions of wheel 29 is engaged by the power roll 30 so that drive wheel29 is rapidly turned until the other recess is located opposite thepower roll in which position the power roll can no longer rotate drivewheel 29. During such forced turning movement of the drive wheel 29,lever 22 moves through its dead center position and arrives in its otherend position when the second recess is located 28 arrives in theposition shown in FIG. 2 and abuts on :12a which dampen its movement.

the blocking projection 32d of the lever 32 of the shift key 37.

Cam 23 turns with lever 22, and during the first part of the turningmovement of the lever 22 from one end position to the intermediateposition, the end portion of the cam track 23a moves along the camfollower so that the type lever carrier 2 is not displaced.Consequently, spring 26 does not have to produce any force for movingthe type lever carrier. At the moment in which the power roll engagesand drives the drive wheel 29, cam follower roller 20 is located in thecurved portion of cam track 23a, and consequently the type lever carrier2 is rapidly moved towards its other end position as long as camfollower 20 is in the curved cam track portion. When cam follower 20 isreceived by the other end portion of cam track 23a, the movement of thetype lever carrier 2 is slowed down since the other end portion of thecam track is also tangential or extends along a circle whose centercoincides with the axis of shaft 21. Near the end of the movement of thetype lever carrier 2 which is guided in the frame of the machine by ballhearing means, not shown, the buffer springs 12 and 12a become effectiveto slow down and dampen the movement of the type lever carrier. At theend of the movement of cam 23 and lever 22, the power roll is no longerefiective since it is located opposite a recess, and spring 26 pullslever 22 and link 27 into a position in which pivot pin 28 abutsprojection 32d of the shift key lever. As explained above, this smalldisplacement has no influence any more on the position of the type levercarrier.

If arresting key 37 was operated instead of key 35, then the type levercarrier is locked in the upper case position until key 37 is againdepressed so that hook 36b releases stop 39. In any event, as soon asshift key lever 32 is released by the operator, spring 34 turns lever 32in counterclockwise direction as viewed in the drawing, so that blockingprojection 32d slides off pivot pin 28 while blocking projection 32cassumes the position shown in FIG. 1 located in the path of movement ofpivot pin 28. Since lever 22 and spring 26 were turned to the positionshown in FIG. 2 during the preceding operation, spring 26 now tends toturn lever 22 in counterclockwise direction to a dead center position,but in an intermediate position before the dead center position, theother toothed peripheral portion of drive wheel 29 is engaged by thepower roll so that drive wheel 29 is turned in clockwise direction withpivot pin 28 moving along a circular path in the upper half of drivewheel 29 as viewed in FIG. 22 until pivot pin 28 abuts blockingprojection 32c. During such turning movement of drive wheel 29, lever 22is turned in counterclockwise direction together with cam 23 so that thecam slot is effective to move the type lever carrier to its normal lowercase position in which it arrives after compression of springs 12 andThe shape of cam track 23a, and particularly of the respective endportion of the cam track, elfects a slowing down of the motion of thetype lever carrier near its end position, and renders the spring 26effective to urge pivot pin 28 against the blocking projection 32]) whenthe power roll is located opposite a recess in the periphery of thedrive wheel 22. In order to reduce the impact, the drive wheel 29preferably consists of an elastic material such as a synthetic ornatural elastomer.

, between a lower case position and an upper case position,

it is not intended to be limited to the details shown, since variousmodifications and structural changes may be made without departing inany way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed and desired to be secured by Letters Patent is:

1. A shifting arrangement comprising, in combination, an element movablebetween two positions; operating means movable between two endpositions, a central dead center position, and two intermediatepositions respectively located between said dead center position andsaid end positions and operatively connected to said element for movingthe same between said positions thereof when moving between saidintermediate positions thereof; biasing means connected to saidoperating means and urging the same toward said dead center position; amember having two positions for holding said operating means in each ofsaid end positions against the action of said biasiug means so that saidoperating means in each of said end positions is urged by said biasingmeans to move through the respective intermediate position toward saiddead center position when said member is shifted from one of saidpositions to the other position thereof; and power means for moving saidoperating means from each of said intermediate positions through saiddead center position to one of said end positions whereby said elementis shifted between said two positions.

2. A shifting arrangement comprising, in combination, an element movablebetween two positions; operating means movable between two endpositions, a central dead center position, and two intermediatepositions respectively located between said dead center position andsaid end positions, and operatively connected to said element for movingthe same between said positions thereof when moving between saidintermediate positions thereof; biasing means connected to saidoperating means and urging the same toward said dead center position; amanually operated member having two positions for holding said operatingmeans in each of said end positions against the action of said biasingmeans so that said operating means in each of said end positions isurged by said biasing means to move through the respective intermediateposition to ward said dead center position when said member is shiftedfrom one of said positions to the other position thereof; and powermeans disconnected from said operating means in said end positions ofthe same, and engagin said operating means in each of said intermediatepositions for moving said operating means from each of said intermediatepositions through said dead center position to one of said end positionswhereby said element is shifted between said two positions.

3. A shifting arrangement for a typewriter and the like comprising, incombination, an element movable oetween an upper case position and aiower case position; operating means movable between two end positionsand operatively connected to said element for moving the same betweensaid positions thereof; resilient biasing means connected to saidoperating means and urging the same toward a'dead center positionlocated intermediate said two end positions; a shift key member havingtwo positions for holding said operating means in each of said endpositions against the action of said biasing means so that saidoperating means in each of said end positions is urged by said biasingmeans to move through an intermediate position toward said dead centerposition when said shift key member is shifted from one of saidpositions to the other position thereof; and power roll means engagingsaid operating means in each of said intermediate 7 positions for movingsaid operating means from each of said intermediate positions throughsaid dead center position to one of said end positions whereby saidelement is shifted between said upper case position and said lower caseposition.

4. A shifting arrangement comprising, in combination, an element movablebetween two positions; operating means 'turnable between two endpositions, a central dead center position, and two intermediatepositions respectively located between said dead center position andsaid end positions, and operatively connected to said eiement for movingthe same between said positions thereof when moving between saidintermediate positions thereof; bias ing means eccentrically connectedto said operating means and urging the same toward said dead centerposition; a manually operated member having two positions for holdingsaid operating means in each of said end positions against the action ofsaid biasing-means so that said operating means in each of said endpositions is urged by said biasing means to move through the respectiveintermediate position toward said dead center position when said memberis shifted from one of said positions to the other position thereof; androtary power means disconnected from said operating means in said endpositions of the same, and engaging said operating means in each of saidintermediate positions for turning said operating means from each ofsaid intermediate positions through said dead center position to one ofsaid end positions whereby said element is shifted between said twopositions.

5. A shifting arrangement for a typewriter or the like, comprising, incombination, an element movable between an upper case position and alower case position; operating means turnable between two end positionsand operatively connected to said element for moving the same betweensaid positions thereof; resilient biasing means eccentrically connectedto said operating means and urging the same toward a dead centerposition located intermediate said two end positions; a shift key memberhaving two positions for holding said operating means in each of saidend positions against the action of said biasing means so that saidoperating means in each of said end positions is urged by said biasingmeans to move through an intermediate position toward said dead centerposition when said shift key member is shifted from one of saidpositions to the other position thereof; and rotary power roll meansengaging said operating means in each of said intermediate positions forturning said operating means from each of said intermediate positionsthrough said dead center position to one of said end positions wherebysaid element is shifted between said upper case position and said lowercase position.

6. A shifting arrangement comprising, in combination, an element movablebetween two positions and having a cam follower; operating means movablebetween two end positions, a central dead center position, and twointermediate positions respectively located between said dead centerposition and said end positions, and including a cam having a cam trackcooperating with said cam followor of said element for moving saidelement etween said positions, and a control member connected to saidcam for movement therewith; biasing means connected to said operatingmeans and urging the same toward said dead center position; a manuallyoperated member having two positions engaging said control member forholding said operating means in each of said end positions against theaction of said biasing means so that said operating means in each ofsaid end positions is urged by said biasing means to move through therespective intermediate position toward said dead center position whensaid member is shifted from one of said positions to the other positionthereof; and power means disconnected from said control member in saidend positions, and engaging said control member in each of saidintermediate positions for turning said operating means from each ofsaid intermediate positions through said dead center position to one ofsaid end positions whereby said element is shifted between said twopositions.

7. A shifting arrangement comprising, in combination, an element movablebetween two positions and having a cam follower; operating meansturnable between two end positions, a central dead center position, andtwo inter mediate positions respectively located between said deadcenter position and said end positions, and including a cam turnableabout an axis and having a cam track cooperating with said cam followerof said element for moving said element between said positions, said camtrack having two end portions substantially concentric with said axis ofsaid turnable cam and differently spaced from the same and anintermediate arcuate portion, and a control member connected to said camfor movement therewith; biasing means eccentrically connected to saidoperating means and urging the same toward said dead center position; amanually operated member having two positions engaging said controlmember for holding said operating means in each of said end positionsagainst the action of biasing means so that said operating means in eachof said end positions is urged by said biasing means to move through therespective intermediate position toward said dead center position whensaid member is shifted from one of said positions to the other positionthereof; and rotary power means disconnected from said control member insaid end positions, and engaging said control member in each of saidintermediate positions for turning said operating means from each ofsaid intermediate positions through said dead center position to one ofsaid end positions whereby said element is shifted between said twoposition-s.

8. An arrangement as set forth in claim 7 wherein said end portions ofsaid cam track extend substantially perpendicularly to each other.

9. An arrangement as set forth in claim 7 wherein said intermediatearcuate portion of said cam track is of sinusoidal shape.

10. An arrangement as set forth in claim 7 wherein said end portions ofsaid cam track extend substantially perpendicularly to each other,wherein one of said end portions is spaced a smaller radial distancefrom the turn ing axis of said cam than the other end portion, andwherein said intermediate arcuate portion is of sinusoidal shape.

11. A shifting arrangement for a typewriter and the like comprising, incombination, an element movable between an upper case position and alower case position and having a cam follower; operating mean-s turnablebetween two end positions and including a cam having a cam track havinga center portion of sinusoidal shape cooperating with said cam followerof said element for moving said element between said positions, and acontrol member connected to said cam for movement therewith; resilientbiasing means eccentrically connected to said operating means and urgingthe same toward a dead center position located intermediate said two endpositions; a shift key member having two positions engaging said controlmember for holding said operating means in each of said end positionsagainst the action of said biasing means so that said operating means ineach of said end positions is urged by said biasing means to movethrough an intermediate position toward said dead center position whensaid shift key member is shifted from one of said positions to the otherposition thereof; and rotary power roll means engaging said controlmember in each of said intermediate positions for turning said operatingmeans from each of said intermediate positions through said dead centerposition to one of said end positions whereby said element is shiftedbetween said upper case position and said lower case position.

12. A shifting arrangement for a typewriter and the like comprising, incombination, an element movable between an uppercase position and alower case position 3 having a cam follower; operatingmeans movablebetween two end positions and including a cam having a main portion andan adjustable portion'mounted on said main portion and forming with thesame an adjustable cam track slot receiving said cam follower for movingsaid element between said positions; resilient biasing meanseccentrically connected to said operating means and urging the sametoward a dead center position located intermediate said two endpositions; a shift key member having two positions for holding saidoperating means in each of said end positions against the action of saidbiasing means so that said operating means in each of said end positionsis urged by said biasing means to move through an intermediate positiontoward said dead center position when said member is shifted from one ofsaid positions to the other position thereof; and rotary power rollmeans engaging said operating means in each of said intermediatepositions for turning said operating means from each of saidintermediate positions through said dead center position to one of saidend positions whereby said element is shifted between said upper caseposition and said lower case position.

13. A shifting arrangement for a typewriter and the like comprising, incombination, an element movable between an upper case position and alower case position including an adjustable member and a cam followerroller mounted on said adjustable member; operating means turnablebetween two end positions and including a cam having a cam track slotreceiving said cam follower roller for moving said element between saidpositions; resilient biasing means eccentrically connected to saidoperating means and urging the same toward a dead center positionlocated intermediate said two end positions; a shift key member havingtwo positions for holding said operating means in each of said endpositions again-st the action of said biasing means so that saidoperating means in each of said end positions is urged by said biasingmeans to move through an intermediate position toward said dead centerposition when said shift key member is shifted from one of saidpositions to the other position thereof; and rotary power roll meansengaging said operating means in each of said intermediate positions forturning said operating means from each of said intermediate positionsthrough said dead center position to one of said end positions wherebysaid element is shifted between said upper case position and said lowercase position.

14. A shifting arrangement for a typewriter and the like comprising, incombination, an element movable between an upper case position and alower case position including an adjustable member and a cam followerroller mounted on said adjustable member; operating means turnablebetween two end positions and including a cam having a main portion andan adjustable portion mounted on said main portion and forming with thesame an adjustable cam track slot receiving said cam follower roller andhaving a sinusoidal center portion and two substantially straighttransverse end portions for moving said element between said positions;resilient biasing means eccentrieally connected to said operating meansand urging the same toward a dead center position located intermediatesaid two end positions; a shift key member having two positions forholding said operating means in each of said end positions against theaction of said biasing means so that said operating means in each ofsaid end positions is urged by said biasing means to move through anintermediate position toward said dead center position when said shiftkey member is shifted from one of said positions to the other positionthereof; and rotary power roll means engaging said operating means ineach of said intermediate positions for turning said operating meansfrom each of said intermediate positions through said dead centerposition to one of said end positions whereby said element is shiftedbetween said upper case position and said lower case positions.

15. A shifting arrangement for a typewriter or the like comprising, incombination, a frame; a shiftable element mounted on said frame formovement between an upper case position and a lower case position; a camfollower secured to said shiftable element; a cam turnably mounted onsaid frame for turning movement between two end positions and having anarcuate cam track slot receiving said cam follower, said cam beingturnable between two end positions for moving said shiftable elementbetween said positions thereof; a lever connected to said cam forturning movement; a rotary power roll mounted in said frame; a drivewheel having two diametrically arrangedperipheral recesses and twoperipheral drive portions intermediate said recesses, said drive wheelhaving an eccentric pivot means connected to said lever so that saiddrive wheel turns with said cam and said lever between two end positionsin which said recesses are located opposite said power roll spaced fromthe same; a resilient means connected to said frame and to said leverand urging said lever to turn with said cam and said drive wheel fromeither of said end positions through an intermediate position toward adead center position, said drive portions of said drive wheel engagingsaid power roll in said intermediate position; a shift key memberoperatively connected to said lever and to said drive wheel and havingtwo positions for holding the same and said cam in either of said twoend positions so that when said shift key member is shifted from one ofsaid positions to the other position, said resilient means turns saiddrive wheel out of said end position until one of said drive portions isengaged by said power roll whereby said power roll turns said drivewheel and said cam through said dead center position toward the otherend position until the other recess is located opposite said power rollwhile said shiftable element is shifted, said resilient means turningsaid drive wheel, said lever and said cam to said other end position.

16. A shifting arrangement for a typewriter or the like comprising, incombination, a frame; a shiftable element mounted on said frame formovement between an upper case position and a lower case position; a camfollower secured to said shiftable element; a cam turnably mounted onsaid frame for turning movement be tween two end positions and having anarcuate cam track slot receiving said cam follower, said cam beingturnable between two end positions for moving said shiftable elementbetween said positions thereof; a lever connected to said cam forturning movement; a rotary power roll mounted in said frame; a drivewheel having two diametrically arranged peripheral recesses and twoperipheral drive portions intermediate said recesses, said drive wheelhaving an eccentric pivot means connected to said lever so that saidcontrol wheel turns with said team and said lever between two endpositions in which said recesses are located opposite said power rollspaced from the same; a resilient means connected to said frame and tosaid lever and urging said lever to turn with said cam and said drivewheel from either of said end positrons through an intermediate positiontoward a dead center position, said drive portions of-said drive wheelengaging said power roll in said intermediate position; a shift keymember having two blocking portions cooperating with said pivot means intwo positions of said shift key member for holding said drive wheel andsaid cam in either of said two end positions so that when said shift keymember is shifted from one of said positions to the other position, saidresilient means turns said drive wheel out of one of said end positionsuntil one of said drive portions is engaged by said power roll wherebysaid power roll turns said drive wheel and said cam through said deadcenter position toward the other end position until the other recess islocated opposite said power roll while said shiftable element isshifted, said resilient means turning said drive wheel, said lever andsaid earn to said other end position in which said pivot It means abutsthe other blocking portion of said shift key member.

17. A shifting arrangement as set forth in claim 16 including a shaftmounted on said frame for turning movement and supporting said lever andsaid cam.

18. An arrangement as set forth in claim 16 and including spring meansfor urging said shift key member to one of said positions thereof sothat said pivot means is released by said other blocking portion whensaid shift key member is released by the operator.

19. A shifting arrangement for a typewriter or the like comprising, incombination, a frame; a shiftable ele ment mounted on said frame formovement between an upper case position and a lower case position; a camfollower secured to said shiftable element; a cam turnably mounted onsaid frame for turning movement between two end positions and having anarcuate cam track slot receiving said cam follower, said cam track slothaving two end portions extending substantially concentrio to theturning axis of said cam, and an intermediate sinusoidal portion betweensaid end portions, said cam being turnable between two end positions formoving said shiftable element between said positions thereof; a leverconnected to said cam for turning movement; a rotary power roll mountedin said frame; a drive wheel having two diametrically arrangedperipheral recesses and two peripheral drive portions intermediate saidrecesses, said drive wheel having an eccentric pivot means connected tosaid lever so that said control wheel turns with said cam and said leverbetween two end positions in which said recesses are located oppositesaid power roll spaced from the same; a resilient means connected tosaid frame and to said lever and urging said lever to turn with said camand said drive wheel from either of said end positions through anintermediate position toward a dead center position, said drive portionsof said drive wheel engaging said power roll in said intermediateposition; a shift key member operatively connected to said lever and tosaid drive wheel and having two positions for holding the same and saidcam in either of said two end positions so that when said shift keymember is shifted from one of said positions to the other position, saidresilient means turns said drive wheel out of one of said end positionsuntil one of said drive portions is engaged by said power roll wherebysaid power roll turns said drive wheel and said cam through said deadcenter position toward the other end position until the other recess islocated opposite said power roll while said shiftable element isshifted, said resilient means turning said drive wheel, said lever andsaid cam to said other end position.

20. A shifting arrangement for a typewriter or the like comprising, incombination, a frame; a shiftable element mounted on said frame formovement between an upper case position and a lower case position;buffer spring means intermediate said shiftable element and said framefor dampening the movement of said shiftable element near said upper andlower case positions; a cam follower secured to said shiftable element;a cam turnably mounted on said frame for turning movement between twoend positions and having an arcuate cam track slot 12 receiving said camfollower, said cam being turnable between two end positions for movingsaid shiftable element between said positions thereof; a lever connectedto said cam for turning movement; a rotary power roil mounted insaidframe; a drive wheel having two diametically arranged peripheralrecesses and two peripheral drive portions intermediate said recesses,said drive wheel having an eccentric pivot means connected to said leverso that said control wheel turns with said cam and said lever betweentwo end positions in which said recesses are located opposite said powerroll spaced from the same; a resilient means connected to said frame andto said lever and urging said lever to turn with said cam and said drivewheel from either of said end positions through an intermediatepositions toward a dead center position, said drive portions of saiddrive wheel engaging said power roll in said intermediate position; ashift key member operatively connected to said lever and to said drivewheel and having two positions for holding the same and said cam ineither of said two end positions so that when said shift key member isshifted from one of said positions to the other position, said resilientmeans turns said drive wheel out of one of said end positions until oneof said drive portions is engaged by said power roll whereby said powerroll turns said drive wheel and said cam through said dead centerposition toward the other end position until the other recess is locatedopposite said power roll while said shiftable element is shifted, saidresilient means turning said drive wheel, said lever and said cam tosaid other end position.

21. A shifting arrangement comprising, in combination, a supportingframe; a shiftable element mounted on said frame for movement betweentwo end positions; spring means intermediate said shiftable element andsaid frame for dampening the movement of said shiftable element nearsaid positions of the same; operating means movable between two endpositions, a central dead center position, and two intermediatepositions respectively located between said dead center position andsaid end positions, and operatively connected to said element for movingthe same between said positions thereof when moving between saidintermediate positions thereof; biasing means connected to saidoperating means and urging the same toward said dead center position; amember having two positions for holding said operating means in each ofsaid end positions against the action of said biasing means so that saidoperating means in each of said end positions is urged by said biasingmeans to move through the respective intermediate position toward saiddead center position when said member is shifted from one of saidpositions to the other position thereof; and power means for moving saidoperating means from each of said intermediate positions through saiddead center position to one of said end positions whereby said elementis shifted between said two positions.

References Cited in the file of this patent UNITED STATES PATENTS

1. A SHIFTING ARRANGEMENT COMPRISING, IN COMBINATION, AN ELEMENT MOVABLEBETWEEN TWO POSITIONS; OPERATING MEANS MOVABLE BETWEEN TWO ENDPOSITIONS, A CENTRAL DEAD CENTER POSITION, AND TWO INTERMEDIATEPOSITIONS RESPECTIVELY LOCATED BETWEEN SAID DEAD CENTER POSITION ANDSAID END POSITIONS AND OPERATIVELY CONNECTED TO SAID ELEMENT FOR MOVINGTHE SAME BETWEEN SAID POSITIONS THEREOF WHEN MOVING BETWEEN SAIDINTERMEDIATE POSITIONS THEREOF; BIASING MEANS CONNECTED TO SAIDOPERATING MEANS AND URGING THE SAME TOWARD SAID DEAD CENTER POSITION; AMEMBER HAVING TWO POSITIONS FOR HOLDING SAID OPERATING MEANS IN EACH OFSAID END POSITIONS AGAINST THE ACTION OF SAID BIASING MEANS SO THAT SAIDOPERATING MEANS IN EACH OF SAID END POSITIONS IS URGED BY SAID BIASINGMEANS TO MOVE THROUGH THE RESPECTIVE INTERMEDIATE POSITION TOWARD SAIDDEAD CENTER POSITION WHEN SAID MEMBER IS SHIFTED FROM ONE OF SAIDPOSITIONS TO THE OTHER POSITION THEREOF; AND POWER MEANS FOR MOVING SAIDOPERATING MEANS FROM EACH OF SAID INTERMEDIATE POSITIONS THROUGH SAIDDEAD CENTER POSITION TO ONE OF SAID END POSITIONS WHEREBY SAID ELEMENTIS SHIFTED BETWEEN SAID TWO POSITIONS.